Preheat the oven to 350°F. Grease a 12-cup muffin pan.
Toast the nuts for 5 to 10 minutes in the oven until fragrant but not dark.
In a small bowl, combine the flour, salt, cinnamon, ginger, nutmeg, cloves, baking soda and baking powder.
In a large bowl, beat the eggs until light. Add the sugar, mixing well. Stir in the pumpkin purée, starter, olive oil and vanilla.
Add the dry ingredients to the pumpkin mixture and stir just until well combined.
Fold in the chopped nuts and raisins, being careful to not overmix the batter.
Divide the batter and fill the muffin pan. Bake for 21 to 23 minutes, until a fork inserted into the center of a muffin comes out clean. Cool in the pan for 10 minutes, then invert onto a rack to cool completely.
Notes
My sourdough starter is a 100 percent hydration starter, meaning it contains equal parts water and flour by weight.